This invention relates generally to agricultural balers and, in particular, to density control mechanisms for such balers.
In the baler art, it is known that bale density may be controlled by changing the position of one or more of the rails of the base case thereby changing the dimensions, i.e., height and width, of the bale chamber. Various types of mechanisms have been provided for performing this function. U.S. Pat. No. 4,125,071 discloses one such type of mechanism that includes an upper channel member disposed above the top rail of the bale case and a lower channel member disposed below the bottom rail of the bale case. These upper and lower channel members are connected by rods having integrally formed crank handles at their upper ends. When the crank handles are turned in one direction, the upper channel member pushes the top rail of the bale case downwardly toward the bottom rail thereof to reduce the height of the baling chamber.
U.S. Pat. No. 4,037,528 discloses another such type of mechanism that includes hydraulic cylinder devices connected at their ends to upper and lower bell cranks which carry rollers contacting the side rails of the bale case. The upper bell cranks are interconnected by a cross beam member attached to the top rail of the bale case. The lower bell cranks are mounted on lugs connected to the bottom rail of the bale case. When the hydraulic cylinder devices are contracted, the upper and lower bell cranks are pivoted in a manner to move the side rails of the bale case toward each other to reduce the width of the baling chamber. The pivoting movement of the upper bell cranks also simultaneously causes the top rail of the bale case to be moved downwardly toward the bottom rail thereof to reduce the height of the baling chamber.